1. Field of the Invention
This invention relates to emergency locator systems utilizing radio beacons for locating lost, incapacitated, or abducted persons. More particularly it relates to a system wherein a search for the missing individual can be initiated by remote activation of a beacon carried by the person.
2. Prior Art
The use of radio beacons and direction finding equipment for locating individuals is well known. One class of such beacons takes the form of a VHF or UHF transmitter adapted to be carried or worn by the person to be located. Means are provided to enable the user to activate the transmitter in an emergency. By way of example, the wrist watch alarm of U.S. Pat. No. 4,591,836 produces a radio signal when it is released from the wrist. The "caller" of U.S. Pat. No. 4,694,284 transmits when its flap-switch is manually operated.
All of these devices require the missing or endangered person to recognize the emergency and perform some act to initiate the beacon's transmission. For the kidnapped infant, exploring toddler, or wandering senior with little or no appreciation of danger and limited manual dexterity, such devices are of little, if any, value. Likewise, even to a robust adult their utility may be severely reduced in the presence of an armed assailant.
A second class of locator device has been adapted for situations in which its use must not be divulged, as for example, to an assailant or abductor. In this category, U.S. Pat. No. 4,535,324 utilizes a beacon activated by squeezing the sides of a finger ring, and U.S. Pat. No. 4,300,129 shows a radio alarm having a secret triggering mechanism contained in a belt buckle. U.S. Pat. No. 3,440,635 employs switch means which can be hidden virtually anywhere on the wearer.
Another category of systems has been developed in which a warning or tracking signal is transmitted upon the passage of a predetermined amount of time, or upon receipt of an actuating signal generated by a triggering device carried and surreptitiously tripped by the person to be aided or located. U.S. Pat. No. 4,259,664 shows such a system for alerting the authorities to a taxicab robbery. U.S. Pat. No. 3,750,131 illustrates a system for schools which is actuated by an inaudible signal generated by the teacher's hand-held transmitter. U.S. Pat. No. 4,606,073 depicts a hybrid system which transmits a prerecorded message over the radio in a police car. None of these systems is applicable for locating a very young, or physically handicapped, or mentally impared person who might be lost or confronted with an emergency. Additionally, none of them provides means for locating the endangered person who has left or been removed from the vehicle containing the beacon.
The present invention is intended to overcome these, and other deficiencies which are inherent in the aforementioned prior art devices and systems.
An object of the invention is the provision of an emergency locator system for locating lost, incapacitated, or abducted persons who because of their age, physical, mental or emotional condition, or other disability are unable to activate the beacon transitter of any of the existing devices or systems.
Another object is the provision of an emergency locator system which can be activated by a concerned individual without the need for any action by the person to be located.
Still another object is the provision of a system for locating an abduction victim which can be initiated remotely without detection by the abductor.
Yet another object is the provision of an emergency locator system which is capable of initiating and supporting concurrent searches for a plurality of missing persons.
A further object is the provision of a personal emergency locator system which is capable of identifying and locating a missing person selectively from among a plurality of participants in the system.
Other objects and features of the invention and its operation will become apparent to the reader from the following summary of the invention and detailed description of several of its preferred embodiments as illustrated in the accompanying drawings.